Page:Popular Science Monthly Volume 46.djvu/620

602 used on wood, excepting the heavier wood scaupers, as they are called (chisels or gouges would perhaps give a better idea of what they are). These could not be used on steel, because the hand of the artist could not force them through the line to be cut; so a more delicate graver is used, and a great many cuts are taken in the same line, thus making it broader and deeper by degrees.

There are several kinds of picture engraving and etching, the most prominent of which are aquatint, mezzotint, stipple, rouletting, and line engraving.

Aquatint is a kind of etching used to get the effect of drawings in India ink, and at one time it was greatly made use of in rendering the drawings of Paul Sandby and our early water-color painters, and particularly prints for drawing-books.

There are many ways of preparing a plate for this work, but the following is the best: Have three different solutions of rosin in rectified alcohol, making them of various degrees of strength, but always thin enough to be quite fluid, the weakest solution being almost colorless. First pour the strongest solution on the plate, which has previously been very carefully cleansed from all oil and grease that would prevent the acid acting upon the steel. When this strongest solution dries it produces a granulation, and you may now bite or corrode the steel with acid through these granulations for your darker tones, stopping out with a varnish made of sealing-wax dissolved in alcohol where the acid is not to operate, or the acid may be applied with a brush where the dark tones are desired. After cleaning the plate as before you proceed with the weaker solutions in the same way; the weakest giving the finest granulations for skies, distances, etc.

The process requires a good deal of stopping out and some burnishing and scraping for the high lights in finishing.

Another style of aquatinting is done by placing a clean plate in an air-tight box where there has been a dust of rosin circulated by means of a bellows attached to the box. The finest of the particles of rosin are allowed to settle on the plate, which is then heated until this dust of rosin sticks to it where it has fallen. The acid is now put to work as before. This gives an even tint something like the other process, the difference being in this cae that the acid bites the plate between the particles of rosin, making a black around a white, whereas in the first process the acid acts through the granulated rosin, producing a black surrounded by a white. An impression of either of these plates, taken in ih.e condition the acid leaves them, would resemble a tint or wash of color on paper.

David Allan engraved his celebrated illustrations of the Gentle Shepherd in this manner. This style of engraving has now